We investigated the potential anticancer effects of oleocanthal (OC) on neuroblastoma cells. Cells were divided into four groups: group 1, neuroblastoma cells were treated with OC; group 2, neurons that differentiated from neuroblastoma cells were treated with phosphate-buffered saline(PBS); group 3, bone marrow derived neuronal (BMDN) cells that were differentiated from bone marrow derived mesenchymal stem cells (BMSCs) were treated with OC; group 4, BMDN cells that were differentiated from BMSCs were treated with PBS. Groups 2 and 4 were control groups. The effects of OC on cell viability, oxidative stress, neurite inhibition and apoptosis at IC50 dose were investigated using MTT analysis, i-NOS and e-NOS measurement, neurotoxicity screening test (NST) and TUNEL staining, respectively. MTT analysis demonstrated that cells were significantly less viable in group 1 than in group 3. i-NOS and e-NOS staining intensity was significantly greater in group 1 than in group 3. NST revealed that OC inhibited neurite growth in both neuroblastoma and BMND cells; inhibition was significantly less in group 3 than in group 1. Significantly more TUNEL labeled cells were found in group 1 than in group 3. We found that OC prevented growth and proliferation of neuroblastoma cells in culture by increasing oxidative stress and apoptosis. We also found that the cytotoxicity of OC is negligible in BMDN cells.
Keywords: apoptosis; cancer; neuroblastoma; oleocanthal; stem cells.